Twelve-Month Outcomes of Standalone iStent Infinite in Primary Open-Angle Glaucoma

Background/Objectives: Evaluation of real-world outcomes of standalone implantation of the third-generation trabecular micro-bypass device (iStent infinite) in eyes with mild to severe primary open-angle glaucoma (POAG). Materials: This retrospective, uncontrolled consecutive case series included eyes undergoing standalone iStent infinite implantation at a single U.S. practice. Outcomes were assessed through 12 months, including changes in intraocular pressure (IOP) and medication burden (primary), proportions achieving IOP ≤ 12/15/18 mmHg and medication categories (secondary), and safety. Subgroup analyses were completed based on preoperative IOP, glaucoma severity, and medication burden. Results: Fifty-one eyes (mean age 66.5 ± 10.8 years) were included. Mean baseline IOP was 20.1 ± 5.4 mmHg on 2.1 ± 1.2 medications. At month 12, the mean IOP decreased to 16.0 ± 3.6 mmHg (-4.1 mmHg, -20.4%; p < 0.001), and mean medications decreased to 1.5 ± 1.2 (-28.6%; p < 0.001). The proportion of eyes achieving IOP ≤ 18/15/12 mmHg increased from 41.2%/15.7%/3.9% to 79.6%/42.9%/16.3%, respectively (all p < 0.001). Medication-free eyes increased from 15.7% to 30.6%, while eyes requiring ≥ 3 medications decreased from 47.1% to 20.4%. Eyes with baseline IOP > 18 mmHg achieved greater IOP reduction (-27.8%), whereas eyes with baseline IOP ≤ 18 mmHg maintained stable IOP with reduced medications. Kaplan-Meier analysis demonstrated 12-month freedom from incisional reintervention of 92.2%. No intraoperative complications occurred. Transient self-resolving hyphema was observed in 3.9% of eyes. A secondary incisional surgery was performed in four eyes (7.8%); no vision-threatening complications were reported. Conclusions: Standalone iStent infinite implantation resulted in significant IOP and medication reductions with a favorable safety profile over 12 months, with outcomes aligned with preoperative treatment goals. These results suggest potential benefit as a less invasive real-world glaucoma intervention, warranting confirmation in larger prospective studies.